RTA? I really don't know of one with the airflow for 100. I have heard of people using TVF4 with the factory coils. The dual coil RBA might get you close, but I have never tried it. I have used the Triple coil at 75 and the single coil RBA to 50-60, but it is too much for me. You might look into an RDTA (Rebuildable Dripping Tank Atomizer) I don't know much about them.
The only RDA that I have that will get that high is my Velocity. I made a dual coil Tiger Wire coil a while back that worked pretty good in the 100 watt range, but it is just something that really isn't enjoyable to me. With the proper build you can get excellent flavor, and enough cloud to fill a room at 50 watts or less.